Cats will be raised with monocular or binocular deprivation and studied as adults. We will use quantitative, electrophysiological techniques to study the effects of deprivation on receptive fields of striate cortical neurons, particularly concentrating on neurons with receptive field locations well away from the area centralis. We will compare these data to those accumulated from normally reared cats. these data will extend previous work and also further elucidate our theory involving a developmental mechanism of binocular competition. The status of neurons in the cortical monocular segment of deprived cats will help determine if, as predicted, this mechanism applies to monocularly, but not binocularly, deprived cats, Other less experiments will be directed at the question of the permanence of deprivation effects in the central visual pathways and at determining some of the environmental conditions necessary for the initiation of binocular competition. Behavioral perimetry testing will be continued in order to test for certain correlates for the above data. BIBLIOGRAPHIC REFERENCES: S.M. Sherman, T.T. Norton and V.A. Casagrande (1975). X- and Y cells in the dorsal lateral geniculate nucleus of the tree shrew (Tupaia glis). Brain Res. 93: 152-157. S.M. Sherman and J.R. Wilson (1975). Behavioral and morphological evidence for binocular competition in the postnatal development of the dog's visual system. J. Comp. Neurol. 161: 183-196.